Inertia responsive fuze



July 7, 1964 1. DELANEY ETAL.

INERTIA RESPONSIVE FUzE 6 Sheets-She??l l Filed March 7, 1963 u, Q/j N@J Inventors JOHN DELANEY VLCTOR JCALLSWORTH y gwnmarb, {md/m Wfgs July7, 1964 J. DELANEY ETAL INERTIA RESPONSIVE FuzE 6 Sheets-Sheet 2 FiledMarch 7, 1963 Attorneys- H m Nw v 1 mu x D ABM H N H f T m wmfn) mw VAM, l I W m h w ML.

lll bwl mm mm om July 7, 1964 Filed March '7, 1963 J. DELANEY ETALINERTIA RESPONSIVE FUZE 6 Sheets-Sheet 3 .F/GJ. @I ,2 ,8

Inventors A ltarneys July 7, 1964 J. DELANEY ETAL INERTIA RESPONSIVEFUZE 6 SheebS-Sheeb 4 Filed March 7, 1963 nl r JOHN DELI Vl CTORHALLSWORTH By i mw Kga/M Y ttorney July 7, 1964 J. DELANEY ETAL INERTIARESPONSIVE FuzE 6 Sheets-Sheet 5 Filed March 7, 1963 Inventors JOHN :DELANEY VICTOR HALLSWORTH By @wma/wn, MAa/m, YMW

July 7, 1964 J. DELANEY ETAL 3,139,828

v INERTIA RESPONSIVE FUZE Filed March 7, 1963 6 Sheer,s-SheerI 6 F/G/Z..

Ltr mmnlors d O HN DE LANEY f\| V lCTOR HA L LSWORT H e L A tlorneysUnited States Patent O 3,139,828 INERTIA RESPONSIVE FUZE John Delaney,Oldham, and Victor Hallsworth, Ashton under Lyne, England, assignors toFerranti, Limited, Hollinwood, England, a company of Great Britain andNorthern Ireland Filed Mar. 7, 1963, Ser. No. 263,528 Claims priority,application Great Britain Mar. 8, 1962 6 Claims. (Cl. 102-78) Thisinvention relates to missile fuze arming devices and is particularly,although not exclusively, concerned with fuze arming devices suitablefor use with rocket powered missiles.

It is an object of the present invention to provide a missile tuzearming device which is certain in operation but which is safe fromaccidental shocks caused during handling of the missile prior to tiring.

According to the present invention a missile fuze arming device includesa weight slidably mounted on a base adapted to be fixed with respect tothe missile, said weight being biassed to a safe position, a detonatorcarrier slidably mounted on said base and separated from said weight bya barrier xed with respect to said base, said detonator carrier beingmechanically connected to said weight by resilient means passing throughsaid barrier, and means for controlling the rate of movement of saiddetonator carrier, the arrangement being such that accelerational forcesacting on said weight when said missile is tired are transmitted to saiddetonator carrier through said resilient means to move said detonatorcarrier, said detonator carrier being moved to an armed position if saidaccelerational forces have a magnitude greater than a desired minimumvalue and act for a minimum time predetermined by said means forcontrolling the rate of movement of said detonator carrier.

lSaid device may further include means for preventing the return of saidweight to the safe position after accelerational forces of a desiredminimum magnitude have been acting for said predetermined time.

One embodiment of the present invention will now be described by way ofexample with reference to the accompanying drawings in which:

FIGURE 1 is a plan view of a missile fuze arming device in accordancewith the invention,

FIGURE 2 is a side elevation of the fuze arming `de 'vice shown inFIGURE 1,

FIGURE 3 is a section along the line 3-3 in FIG- URE 2,

FIGURE 4 is a section along the line 4-4 in FIG- URE 2,

FIGURE 5 is a simplied side elevation showing a modiiication of the fuzearming device shown in FIG- URE 1, j

FIGURE 6 is a section along the line 6 6 of FIG- URE 5, i

t FIGURE 7 is a section along the line 7--7of FIG- URE 5,

FIGURE 8 is a side elevation of the device shown in FIGURE 5 during theboost period,

FIGURE 9 is a section along the line 9-9 of FIG- URE 8, j j FIGURE 10 isa section along the line 10-10 of FIG- URE 8,

FIGURE 11 is a side `elevation vof the device shown in FIGURE 5 at theend of the boost period,

FIGURE 12 is a section along the line 12-'12 of FIG- URE 11, and

FIGURE 13 is a section along the line 13-13 of'FIG- URE 11.

Referring now to FIGURES 1 to 4 of the drawings the missile fuze armingdevice shown includes a base 1 on Fice which are mounted end plates 2and 3 and a central barrier 4. Two rods 5 and 6 extend between the endplates 2 and 3 and a further rod 7 extends between the end plate 2 andthe barrier 4. A weight 8 is slidably mounted on the rods 5, 6 and 7 formovement between the end plate 2 and the barrier 4, and a detonatorcarrier 9 is slidably mounted on the rods 5 and 6 for movement betweenthe barrier 4 and the end plate 3. The weight 8 is biassed towards theend plate 2 by means of two compression springs 10 and 11 mounted on therods 5 and 6 and recessed into the weight 8 and the barrier 4. A rod 12is rigidly secured to the detonator carrier 9 and extends through thebarrier 4 and passes freely through an aperture in the weight 8. Acompression spring 13 is mounted on the rod 12 and extends between thedetonator carrier and the near side of the weight 3 passing freelythrough the barrier 4, and a further compression spring 14 is mounted onthe rod 12 and extends between the inner wall of a recess 15 in theweight 8 and an abutment formed by a screw 16 threaded into the end ofthe rod 12.

The detonator carrier 9 has a detonator 17 secured by two screws 18 andcarries electrical contacts 19 which co-operate with contacts 2t) and 21mounted on a platform 22 fixed with the respect to the base 1. Theplatform 22 carries an igniter 23 connected to an electrical tiringcircuit by means of contact 24 which co-operates with a further contacton the inside of a cover member (not shown). In order to regulatemovement of the detonator carrier 9 it is provided with a rack 25 whichcooperates with a gear train 26 to drive anescapement including a pallet27.

The detonator carrier 9 is also provided with a groove 28 extendingalong one side and having a short vertical groove 29 forming an outletnear one end. An arm 30 projecting transversely from a rod 31 rides inthe groove 28. The rod 31 extends between the end plate 2 and thebarriei 4 and projects beyond barrier 4. A spring 32 biasses rod 31 torotate in the direction of the arrow shown in FIGURE 3. In the safecondition the rod 31 is prevented from rotating by means of a stop inthe form of a quadrant 33 which engages with a projection 34 extendingalong the full length of the weight S, the quadrant 33 being mounted onthe rod 31 in such a position that when the weight 8 is against thebarrier 4 the quadrant 33 is just clear of the forward end of theprojection 34.

In operation the arming device is mounted in the missile with the rods 5and 6 parallel to the accelerational axis. When the missile is tired, ifthe accelerational forces have a magnitude greater than a desiredminimum value determined by the springs 10 and 11 the weight Sis causedto move 'back against the action of the springs 10 and 11 until it isprevented from further movement by the lbarrier 4. The spring 13 istherefore compressed and causes the detonator carrier 9 to movebackwards, the rate of this movement being controlled by the gear train26 and the escapement. With the weight 8 against the barrier 4 toquadrant 33 is freed from the projection 34, but the rod 31 is preventedfrom rotating until the detonator carrier 9 has moved suiiciently farfor the arm 3i) to be freed upon reaching the vertical groove 29, thetime taken for the detonator carrier to travel this distance beingpredetermined by a suitable choice of eS- capement. Thereafter the rod31 rotates for a quarter of a turn and the quadrant 33 is then in such aposition as to prevent the return of the weight 3. The detonator carrier9continues moving due to the compression of the spring 13 and just priorto the carrier 9 reaching the armed position the rst pinion in the geartrain 26 runs oit the rack 23 so that the detonator carrier`9 suddenlymoves into the armed position and the contact 19 engages the contact 21to complete the electrical tiring circuit. In this position the igniter23 and the Vdetonator 17 are in line with a chemicallyy explosive pellet(not shown) contained in an aperture 35 in the base 1.

It Will be seen that the gear train 26 is protected from accidentalshock loads imposed on the weight 8. If the weight 8 is moved towardsthe barrier 4 the spring 13 prevents the shock from being transmitted tothe gear train 26 and should the weight 8 be suddenly returned towardsthe end plate 2 the spring 14 similarly prevents the shock from beingtransmitted to the gear train 26. In order to arm the missile the Weight8 must be held against the barrier 4 for a sufficient time to elapsesuch that the detonator carrier 9 moves to bring the vertical groove 29in line with the arm 30. This time may be made of any required length bysuitably choosing the escapement 27 and a suitable length of time is21/2 seconds. Also, unless the acceleration reaches the minimum valuerequired the mechanism will not arm since the weight 8 will not havesufficient force to fully compress the springs and 11 and hence will notreach the barrier 4. The quadrant 32 will therefore be prevented fromrotating by the projection 34 and the arm 30 will prevent ythe detonatorcarrier 9 from moving into the armed'position. The missile is thereforefully protected from accivdental shocks caused during handling and,furthermore, will not arm until the missile has travelled a safedistance from the firing point.

In the fuze arming device described above the detonator carrier 9 ismoved to the armed condition at a fixed time after firing, the timebeing determined by the gear train 26 and the escapement. In somemissiles, however, the boost period during which the missile is beingaccelerated varies with the ambient temperature and if the missilebecomes armed at a xed time after firing the arming distance willsimilarly vary with the ambient temperature.

train and escapement and the components of the electrical firing circuithave been omitted. The device differs from that described above in thatthe rod 31 is provided with a quadrant 40 which is positioned such thatwhen the weight 8 is against the barrier 4 the quadrant 40 is well clearof the forward end of the weight 8. The rod 31 is also provided with astop 41 positioned adjacent the barrier 4. The Weight 8 has a projection42 which co-operates with 'the quadrant 40 to prevent rotation of therod 31 during the intermediate stage of the travel of the weight 8.

Before firing the conditions are as shown in FIGURES 5, 6 and 7, the rod31 being prevented from rotating by the engagement of the arm 30 in thegroove 28 in the detonator carrier 9. When the missile is firedaccelerational forces having a magnitude greater than the desiredminimum value cause the weight 8 to move back to the barrier 4 and thedetonator carrier 9 is moved back in the manner previously describeduntil the arm 30 reaches the groove 29 as shown in FIGURE 8. The rod 31then rotates until the stop 41 engages the weight 8 (FIGURE 9) toprevent the release of the arm 30 from the groove 29 (FIGURE 10). Thearm 30 therefore effectively locks the detonator carrier 9 during theboost period. At the end of the boost period the weight 8 starts to moveforward under the action of the springs 10 and 11 (FIG- URE 1. As theweight 8 moves forward, however, the stop 41 is released and the rod 31rotates and positions the quadrant 40 such that it prevents furtherforward movement of the weight 8 (FIGURE 11). Rotation of the rod 31also releases the arm 30 from the groove 29 (FIG- URE 13) andthedetonator carrier 9 is then moved to the armed position as previouslydescribed. In this manner thermissile becomes armed at the end of theboost period iand not at a fixed time after firing.

The total boost delivered to the missile is constant and may bedelivered at a high rate for a short time when the ambient temperatureis high `or at a slower rate for a longer time when the ambienttemperature is low but by delaying the arming of the missile until theend of the boost period the variations of the distance travelled by themissile before it is armed due to variations of the ambient temperatureare considerably less than Yif the missile is armed at a fixed timeafter firing. I

What we claim is:

1. A missile fuze arming device including a base adapted to be fixedwith respect to the missile, a weight mounted on said base forlongitudinal slidable movement relative thereto parallel to theaccelerational axis of the missile from a safe position to an armingposition, biassing means for biassing said weight to` said safeposition, a vdetonator carrier mounted on said base for longitudinalslidable movement relative thereto parallel to the accelerational axisof the missile from a safe position to an armed position, a barrierfixed with respect to said base between said weight and said detonatorcarrier for preventing direct mechanical contact between said weight andsaid detonator carrier, resilient coupling means passing through saidbarrier for resiliently coupling said weight to said detonator carrierirrespective of the direction of `movement of said Weight, delay meansfor controlling the and said detonator carrier has moved to apredetermined position intermediate its safe and armed positions.

2. A missile fuze arming device as claimed in claim 1 including meansfor preventing said detonator carrier from moving to its armed positionwhen subject to an accelerational force having a magnitude greater thanthe minimum force required to overcome said biassing means and move saidweight to its arming position.

3. A missile fuze arming device as claimed in claim 1 in which said stopmeans includes a rod rotatably mounted on said base having first andsecond transverse projections, means biassing said rod to rotate insucha direction as to move said first transverse projection into thepath of said Weight, a groove extending lengthwise of said detonatorcarrier and adapted to receive said second transverse projection toprevent rotation of said rod, and an outlet from said groove sopositioned that said second transverse projection may be released fromsaid groove to permit rotation of said rod by said biassing means whensaiddetonato'r carrier reaches said predetermined position. l 't 4. Amissile fuze arming device as claimed in claim 3 in which said rod isalso provided with a third transverse projection adapted to so engagesaid weight when said weight is in its arming position as to permit onlypar- Vtial rotation of said rod toan extent such that said second Athanthe minimum force required to overcome said biassing means and move saidweight to its arming position, said first transverse projection being sopositioned as to allow sufficient forward movement of said weight torelease said third transverse projection when said accelerational forcefalls to a magnitude less than said minimum force, thereby permittingrelease of said ysecond trans- 3,139,828 5 verse projection andcontinued movement of said det- References Cited in the le of thispatent onator carrier towards its armed position. UNITED STATES PATENTS5. A missile fuze arming device as claimed in claim 1 714,540 GreatBritain Sept. l, 1954

1. A MISSILE FUZE ARMING DEVICE INCLUDING A BASE ADAPTED TO BE FIXEDWITH RESPECT TO THE MISSILE, A WEIGHT MOUNTED ON SAID BASE FORLONGITUDINAL SLIDABLE MOVEMENT RELATIVE THERETO PARALLEL TO THEACCELERATIONAL AXIS OF THE MISSILE FROM A SAFE POSITION TO AN ARMINGPOSITION, BIASSING MEANS FOR BIASSING SAID WEIGHT TO SAID SAFE POSITION,A DETONATOR CARRIER MOUNTED ON SAID BASE FOR LONGITUDINAL SLIDABLEMOVEMENT RELATIVE THERETO PARALLEL TO THE ACCELERATIONAL AXIS OF THEMISSILE FROM A SAFE POSITION TO AN ARMED POSITION, A BARRIER FIXED WITHRESPECT TO SAID BASE BETWEEN SAID WEIGHT AND SAID DETONATOR CARRIER FORPREVENTING DIRECT MECHANICAL CONTACT BETWEEN SAID WEIGHT AND SAIDDETONATOR CARRIER, RESILIENT COUPLING MEANS PASSING THROUGH SAID BARRIERFOR RESILIENTLY COUPLING SAID WEIGHT TO SAID DETONATOR CARRIERIRRESPECTIVE OF THE DIRECTION OF MOVEMENT OF SAID WEIGHT, DELAY MEANSFOR CONTROLLING THE RATE OF LONGITUDINAL MOVEMENT OF SAID DETONATORCARRIER, STOP MEANS MOUNTED ON SAID BASE AND COOPERATING WITH BOTH SAIDWEIGHT AND SAID DETONATOR CARRIER, SAID STOP MEANS HAVING A FIRSTPOSITION, IN WHICH SAID WEIGHT AND SAID DETONATOR CARRIER ARE BOTH FREETO MOVE, AND A SECOND POSITION, IN WHICH SAID WEIGHT IS PREVENTED BYSAID STOP MEANS FROM RETURNING TO ITS SAFE POSITION AND SAID DETONATORCARRIER IS STILL FREE TO MOVE, AND MEANS OPERABLE TO MOVE SAID STOPMEANS FROM SAID FIRST POSITION TO SAID SECOND POSITION WHEN SAID WEIGHTIS IN ITS ARMING POSITION AND SAID DETONATOR CARRIER HAS MOVED TO APREDETERMINED POSITION INTERMEDIATE ITS SAFE AND ARMED POSITIONS.